Engine running hot
Discussion
I have a standard 3.6 litre engine that to my mind is running too hot. Too often it runs between 96 to 102 degrees. Both fans are working and I'm not losing any water I know we have had some glorious weather, but this has never affected any other car I've owned in the past. So why should this car be any different?
What should I be doing to improve the running temperature?
What should I be doing to improve the running temperature?
Personally I wouldn't worry 
in traffic it will rise up to those levels, when flying along it will drop down to low 90's. Mines got additional scoops and vents which improve airflow, reducing temp. however the t350's are pretty resilient. Some have gone for the ally rad to improve things, mines and original and i have no issues.
in traffic it will rise up to those levels, when flying along it will drop down to low 90's. Mines got additional scoops and vents which improve airflow, reducing temp. however the t350's are pretty resilient. Some have gone for the ally rad to improve things, mines and original and i have no issues.Edited by ShiDevil on Wednesday 17th July 23:20
Two points of interest...
- the dash and actual engine temperature are usually always a few degree out. Mine for example is 5 out. The dash reads 5 more than the engine actually is
- you should not start to panic unless the engine hits about 107+. There has been some argument on this figure in the past, but that is what I was told by a few TVR technicians
alex_gray255 said:
Two points of interest...
How did you measure true temperature rather than that reported by the dash?- the dash and actual engine temperature are usually always a few degree out. Mine for example is 5 out. The dash reads 5 more than the engine actually is
It would be interesting to know what the difference is for my car (which never gets about ~ 92 and has a new Alloy Rad).
Sevenman said:
It would be interesting to know what the difference is for my car (which never gets about ~ 92 and has a new Alloy Rad).
Has you alloy rad made a difference? Because despite reassurances from Shidevil and Alex Gray255. I am feeling a little uneasy with the way my car is running. For instance on a cool day my normal operating temperature will be anything between 89 to 96 degrees. With the current climate, it is well in excess of that. And yesterday when I saw it hit 102, I pulled over to let the car cool down.Lone Star said:
Has your alloy rad made a difference?
It has made a difference to the amount of coolant dripping from he radiator (now none).I don't think it made much difference to temperature, but I don't have records of before / after. I don't think it got as hot as you describe when on the standard radiator, but it was a while back it was changed.
Checking the true temperature seems like a good place to start, an alloy rad is an expensive thing to change if the original isn't leaking.
Lone Star said:
Because despite reassurances from Shidevil and Alex Gray255. I am feeling a little uneasy with the way my car is running.
If you are unhappy with the temperatures, then take it to a TVR engine specialist (i.e. Power) and get them to check it out for you.The worse that can happen is that you spend money to get some peace of mind.
Edited by alex_gray255 on Thursday 18th July 16:01
Correct me if I am wrong, but I've always been under the understanding that there are two temperature sensors in the engine bay. One which feeds the dash readout and is in a hotter part of the engine, and one which feeds the actual ECU and switches the fans on and off (which is in a slightly cooler part of the engine). I was always led to believe that this is why the dash always reads between 5 and 10 degrees higher than the ECU (fan) temperature.
The only way to tell how hot the engine is actually running (to control the fans) is, as has been mentioned, plug it in to the diagnostic software. All you need is a cable off ebay (to plug into the ECU), an very old laptop (with the old serial port), and the software.
The only way to tell how hot the engine is actually running (to control the fans) is, as has been mentioned, plug it in to the diagnostic software. All you need is a cable off ebay (to plug into the ECU), an very old laptop (with the old serial port), and the software.
The S6 develops an incredible heat. Where I live we have currently over 30 degrees in the shade and around 40 in the sun. If the engine is idle in 40 degrees sun, it can be "cooled" by the 2 fans, but I doubt it will survive if it goes over 40.
However as long I can drive, temps stay around 90 (on the dash) but when caught in traffic jam it immediately climbs to around 110 and fans kick in. I checked the temps on the ECU and it seems they are about 15 degrees apart! So whats the reason to trust an electrical sensor more than a mechanical ?
I measured the resistance of the NTC temp sensor and checked it against the data-sheet and the value shown by the ECU. They are accurate to around 5%.
So I checked how hot it really got: (and the dash showed around 90)
BTW: The exhaust gets above 350 ... (beyond any RTV gasket sealant)
However as long I can drive, temps stay around 90 (on the dash) but when caught in traffic jam it immediately climbs to around 110 and fans kick in. I checked the temps on the ECU and it seems they are about 15 degrees apart! So whats the reason to trust an electrical sensor more than a mechanical ?
I measured the resistance of the NTC temp sensor and checked it against the data-sheet and the value shown by the ECU. They are accurate to around 5%.
So I checked how hot it really got: (and the dash showed around 90)
BTW: The exhaust gets above 350 ... (beyond any RTV gasket sealant)
Edited by crypto on Monday 22 July 22:34
I was panicking about Chimaera engine temperatures of around 90-95 degrees in traffic in the recent warm weather, cooling fans running almost non-stop. Temps were actually cooler going flat out (8 mpg) on a recent trackday.
Then I was reminded that the boiling point of water in a pressurised system is well in excess of 100 degrees.
And I drove my diesel Audi at 5am with the outside temperature at 13 degrees........dashboard temperature 90 degrees.
If its not running roughly then it's probably fine IMHO.
Then I was reminded that the boiling point of water in a pressurised system is well in excess of 100 degrees.
And I drove my diesel Audi at 5am with the outside temperature at 13 degrees........dashboard temperature 90 degrees.
If its not running roughly then it's probably fine IMHO.
I had my Tuscan down in France and Spain a few years back and the temps were in the high 30s/low 40s. In traffic, the fans were running most of the time but it never got up to 100 degrees, even sitting with the aircon on. The car is decatted and I had replaced my original alloy rad with a copper/brass one (marginally heavier but easier to repair) not long before the trip so the cooling system had been flushed.
ackbullchang said:
Peter, can you confirm what you mean by NTC sensor, and explain how you measured the resistance please?
Thanks
NTC means "negative temperature coefficient". An electronic resistor measured in Ohm. The resistor is temperature sensitive and reduces its value the higher the temperature is (in contrast to a P(ositive)TC sensor). Thanks
To measure the sensors value, remove the airbox and unplug the connector from the sensor (underneath throttle body 5) and measure its value with an ordinary multimeter set to the 2k or 20k ohm resistance range.
I couldn't find the original data-sheet, the equivalent type from bosch seems to be part number "0 280 130 023" but has since been superseeded by :
http://www.bosch-motorsport.de/en-US/literature/en...
In the data-sheet you'll find the temp/resistor values
Sevenman said:
Good test using an IR camera. Not many owners have one of their as part of their diagnostics kit.
Is that from your work, or do you just prefer longer wavelenths than visible?
This is from work, I can't afford to have my own one Is that from your work, or do you just prefer longer wavelenths than visible?
BTW: all information given here is to the best of my knowledge but without guarantee
Mine used to regularly get into the 100's in Queensland, so I had the alloy rad, lower thermostat and uprated fans fitted - now it will get to turn the fans on in the low 90s but not any higher.
One thing I do find odd is that when driving on the highway (60ish mph) in circa 15 degree weather, the engine will still stay up round the 90 degree mark with the fans frequently flicking on and off (the relay noise gets annoying). Any thoughts?
One thing I do find odd is that when driving on the highway (60ish mph) in circa 15 degree weather, the engine will still stay up round the 90 degree mark with the fans frequently flicking on and off (the relay noise gets annoying). Any thoughts?
Mattt said:
Mine used to regularly get into the 100's in Queensland, so I had the alloy rad, lower thermostat and uprated fans fitted - now it will get to turn the fans on in the low 90s but not any higher.
One thing I do find odd is that when driving on the highway (60ish mph) in circa 15 degree weather, the engine will still stay up round the 90 degree mark with the fans frequently flicking on and off (the relay noise gets annoying). Any thoughts?
Congrats, you crossed the border of 15000 posts One thing I do find odd is that when driving on the highway (60ish mph) in circa 15 degree weather, the engine will still stay up round the 90 degree mark with the fans frequently flicking on and off (the relay noise gets annoying). Any thoughts?
incredible !I don't see a reason why your fans should turn on in the low 90s with your modifications. The temp is measured by the ECU and it will turn on one fan at 92 and the other at 94. I believe both are turned off at 88.
At 60mph you are pushing more air thru the rad than the fans can ever do. First thought was you probably hear the A/C going on/off, but this can't be @ 15 degrees
In my car, I can't hear the relays or at least I never noticed. Aren't they somewhere in the boot ? To make a long story short, I have no idea how the water-temp is regulated to 90 degrees, if at all. The oil/water heat-exchanger does also its part, but with 60mph @ 15C, I would struggle to get the engine to operating temperatures.
Mattt said:
Mine used to regularly get into the 100's in Queensland, so I had the alloy rad, lower thermostat and uprated fans fitted - now it will get to turn the fans on in the low 90s but not any higher.
One thing I do find odd is that when driving on the highway (60ish mph) in circa 15 degree weather, the engine will still stay up round the 90 degree mark with the fans frequently flicking on and off (the relay noise gets annoying). Any thoughts?
Assuming your coolant isn't low, it sounds like the coolant isn't being circulated properly through the rad? Maybe an air lock?One thing I do find odd is that when driving on the highway (60ish mph) in circa 15 degree weather, the engine will still stay up round the 90 degree mark with the fans frequently flicking on and off (the relay noise gets annoying). Any thoughts?
The cooling on the T350 is woeful, look at the angle/placement of the rads and the way air is expelled from the engine bay compared to other TVRs (Tuscan owners will note that the same engine they'll see water temps a lot lower than that on the T350). Myself and my mechanic are going to look into a form of front splitter to help try and create a vacuum under the engine to pull air through.
I have the Power uprated fans but in this weather will often see 100deg on the water temp, add another 5-8 degrees should I turn the air-con on.
I have the Power uprated fans but in this weather will often see 100deg on the water temp, add another 5-8 degrees should I turn the air-con on.
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